Influence of pollution along a natural gradient and in a mesocosm experiment on biomass-size spectra of benthic communities

Abstract

Biomass-size spectra of benthic communities at 6 sites in Frierfjord/Langesundfjord. Norway, and in 4 experimental mesocosm basins at Solbergstrand, Nonuay, are presented, as evaluated during the GEEP Workshop. Fjord sites were selected to represent a pollutant gradient based on known sources of pollution. Three of the mesocosm basins were exposed to different dosing levels of a mixture of diesel oil and copper for ca 3 mo; the 4th basin served as control. Communities from the fjord sites showed differences in size-structure that could be related, in part, to their proximity to pollution sources. Mesocosm communities revealed no significant differences in size-structure attributable to dosing level.

Characteristic benthic size spectra: potential sampling artefacts

“…yielding a biomass spectrum with a slight positive slope more representative of observed benthic biomass spectra (e.g. see Schwinghamer 1988). Again, an obvious biomass trough was produced be - tween the meiobenthos and macrobenthos (Fig.…”

“…Schwinghamer (1981) originally employed X8 classes (a X2 scale of equivalent spherical diameter), later switching to a X2 scale (Schwinghamer 1988). To simplify the simulation of sampling benthic body size distributions, the following assumptions were employed: (1) there is a continuous distribution of body sizes through classes 0 to 30; (2) all organisms are perfect spheres (increased complexity in body form is considered in Supplement 1 at www.int-res.com/articles/suppl/m487p001_supp.…”

“…These questions were posed based on an acceptance of the classical work of Schwinghamer (1981, 1985, 1988, Schwinghamer et al 1986), who described trimodal benthic biomass spectra with modes corresponding to the conventional body size definitions of micro-, meio-, and macrobenthos. Schwing hamer's work was soon apparently supported by the work of Warwick (1984) and co-authors (Warwick & Clarke 1996, Warwick & Joint 1987, Kendall et al 1997, who de scribed bimodal species body size spectra for benthic invertebrates with the modes again matching standard definitions of the meio-and macrobenthos.…”

Benthic communities along a littoral of the Central Adriatic Sea (Italy)

“…Furthermore, previous findings within the literature do not only suggest nutritional interactions or competition, but also the presence of some synergistic relationships (Tenore and Rice 1980;Reise 1985;Tita et al 2000). It is so evident that the benthic response to changes in environmental conditions (from climate changes to pollution events) can be better understood by taking into account the whole benthic size spectrum (Schwinghamer 1988;Danovaro 2000;Austen and Widdicombe 2006). Nevertheless, to our knowledge, data sets on bacteria, meiofauna and macrofauna have only sporadically been collected in a simultaneous manner in the Mediterranean (Albertelli et al 1999;Covazzi-Harriague et al 2006;Papageorgiou et al 2007) and never in the Adriatic Sea.…”

Predicting abundance-body mass relationships in benthic infaunal communities

“…An understanding of the factors responsible for shaping abundance-body mass relationships in the absence of human impacts has applied significance, since changes in these relationships may be a good indicator of the effects of pollution or physical disturbance (Schwinghamer 1988, Duplisea et al 2002.…”